The CERT/CC recommends the following practices to home users:

Consult your system support personnel if you work from home

Use virus protection software

Use a firewall

Don’t open unknown email attachments

Don’t run programs of unknown origin

Disable hidden filename extensions

Keep all applications (including your operating system) patched

Turn off your computer or disconnect from the network when not in use

Disable Java, JavaScript, and ActiveX if possible

Disable scripting features in email programs

Make regular backups of critical data

Make a boot disk in case your computer is damaged or compromised

source:- http://www.cert.org/tech_tips/home_networks.html